Windows Defender, everything else is malware itself.

If you want to be extra sure, check stuff using virustotal.com

Commonsense 2023

Windows defender for active threats malwarebytes for scanning downloads/files. Alternatifely: sandbox a Linux distro.

You literally don't need anything more these days.

On Windows, just use the built-in Windows Defender. On Linux, I recommend ClamAV + ClamTK. On Android, Hypatia.

If you think you have malware, this is a pretty good guide to remove it.

I'd also strongly recommend using and configuring a content blocker like uBlock Origin in your browser, as well as using a DNS level blocker like NextDNS.

If you have a multilayered setup like this, then I think you're pretty good and it'll be not impossible, but much harder to get malware or be infected. Just use common sense as always.

Windows Defender.

If for Windows which I think it is then I highly recommend you to check The PC Security Channel, I have always recommended everyone to use a 3rd party AV but now with my ESET internet security subscription about to end in a month I'm planning to give a windows defender a go

None.

Have a good backup strategy and nuke the OS/restore data from backup when needed.

I wouldn't trust any antivirus to clean everything properly after my machine has been infected.

Windows defender (built in) on Windows, none on any other OS. Keep in mind that you need to uninstall existing AV for Defender to activate.

clamav / clamtk and nothing proprietary because antivirus gets access to everything. it is worth noting that these are antimalware more than antivirus.

Linux